Abstract: The present invention provides a process and host cell for use in increasing the amount of a desired protein by a cell line. The process and the cell line use a first transcription unit containing a gene for a transactivator protein to control the transactivation of a second transcription unit such that the amount of the desired protein expression can be increased without adversely affecting the cell growth. Preferred transactivator proteins are derived from EIA.

Abstract: Methods for enhancing the production of tissue plasminogen activator (tPA) in cell culture are disclosed. The methods involve culturing tPA-producing cells in growth media supplemented with an alkanoic acid or salt thereof at a concentration which enhances tPA production. The most preferred methods utilize butyric acid or sodium butyrate at a concentration of between 0.5 mM and 2.5 mM.

Abstract: Methods for enhancing the production of tissue plasminogen activator (tPA) in cell culture are disclosed. The methods involve culturing tPA-producing cells in growth media supplemented with an alkanoic acid or salt thereof at a concentration which enhances tPA production. The most preferred methods utilize butyric acid or sodium butyrate at a concentration of between 0.1 mM and 10 mM.

Abstract: A myeloma cell-line transformed with a vector including a gene coding for a eukariotic polypeptide and a non-immunolglobulin promoter such that expression occurs of the gene coding for the eukariotic polypeptide, directed by the non-immunoglobulin promoter. The promoter may be a viral promoter, such as an SV40 promoter, a Rous sarcoma virus long terminal repeat or a Moloney murine leukemia long terminal repeat, or a non-viral promoter such as the mouse metallothionein promoter. Rat and mouse host myeloma cell-lines such as the rat YB/2/3.0 Ag20 hybridoma, the mouse SP-20 Ag hybridoma and the mouse NSO hybridoma are employed. The production of tissue plasminogen activator (tPA) is exemplified.

Abstract: The present invention relates to vectors useful for transforming a lymphoid cell line to glutamine independence. The vectors comprise an active glutamine synthetase (GS) gene as well as a heterologous gene of interest to be expressed. The preferred embodiments encompass vectors wherein the heterologous gene is expressed from a relatively strong promoter and the GS gene is expressed from a relatively weak promoter. In one example, the heterologous gene is operatively linked to the hCMV-MIE promoter and the GS gene is operatively linked to the SV40 early region promoter.

Abstract: We have discovered that the stability of a dilute peroxidase-containing solution is greatly enhanced by the addition of a specific substrate for the peroxidase, in the absence of peroxide. We provide a peroxidase-containing reagent consisting of a buffered aqueous solution comprising a peroxidase or a peroxidase conjugate and a specific substrate for the peroxidase, in the absence of peroxide. The peroxidase may be a free peroxidase but for assay purposes is preferably a peroxidase bound to a specific binding component of an assay, to form a peroxidase conjugate. The peroxidase conjugate is preferably a conjugate between a peroxidase and an antigen or an antibody, most preferably an antibody. The peroxidase is preferably horseradish peroxidase.

Abstract: Adherent animal cells are grown in suspension in a nutrient medium in which the molar ratio of total inorganic ions and total amino acids is reduced when compared with the corresponding ratio in known nutrient media, and is maintained at a level at which little or no cell aggregation occurs. Further, the nutrient medium contains 10:1 to about 1:1 molar ratio of total inorganic ions to total amino acids. In one further embodiment, the nutrient medium contains a total sodium ion concentration in the range of 75 to 120 mM (millimole), a total chloride ion concentration in the range of 50 to 90 mM and a total amino acid content of 20 to 50 mM. The adherent animal cells include mammalian cells such as cells belonging to a human, rat, mouse or hamster. Chinese Hamster Ovary Cells (CHO cells) are cultured using the process of the disclosed invention.

Abstract: The present invention provides a process and host cell for use in increasing the amount of a desired protein produced by a cell line. The process and the cell line use a first transcription unit containing a gene for a transactivator protein to control the transactivation of a second transcription unit such that the amount of desired protein expression can be increased without affecting adversely cell growth. Preferred transactivator proteins are derived from E1A.

Abstract: A time-resolving luminescence binding assay involves a metal-labelled binding partner comprising a luminescent transition metal complex covalently attached to a binding partner such as an antigen or antibody. Ruthenim, iridium, osmium, and chromium luminescent complexes are described.

Abstract: The present invention relates to a peroxidase-containing reagent comprising a buffered aqueous solution of a peroxidase conjugate and a substrate for the peroxidase, in the absence of peroxide. The invention further relates to a method of stabilizing the peroxidase activity of a buffered aqueous solution containing a peroxidase conjugate. Further, the invention relates to a tetramethylbenzidine peroxidase substrate reagent and to a method of preparing same.